Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
Most Important Selected Qs for JEE AdvancedPhysicsRotational Motion

A disc shaped body (having a hole as shown in the figure) of mass m =10 ~kg and radius R = 10 9 ~m is performing pure rolling motion on a rough horizontal surface. In the figure point O is geometrical center of the disc and at this instant the centre of mass C of the disc is at same horizontal level with O . The radius of gyration of the disc about an axis passing through C and perpendicular to the plane of the disc

Correct answer

6

Step-by-step solution

considering torque of real and pseudo force in the frame of P , aligned & =m g R 2 +m ^2 R R 2 & =m g R 2 +m g R R R 2 =m g R & I_p=m ( R 2 )^2+m (R^2+ R^2 4 )= 3 2 m R^2 & = 2 m g R 3 m R^2 = 2 g 3 R =6 rad / s ^2 aligned

Practice Rotational Motion on Quantrex Academy →

More from Rotational Motion

Consider a large disk of radius R and two smaller disks, each of radius r = R/50 , lying on its circumference, as shown in the figure. The smaller disks are initially in contact wi 2026A solid cylinder of radius R rolls without slipping with a center of mass speed v₀ = gR 3 on a horizontal surface with a vertical edge, as shown in the figure. Here, g is the accel 2026List-I shows four planar structures made of uniform solid rods each of mass m and length l . In the List-II the possible moment of inertia of these structures about an axis OCO' , 2026Passage: A uniform circular disk of radius 0.2 m and mass 1 kg is pivoted at its top point C such that it can rotate freely around C in the XY plane, as shown in the figure. Initia 2026Passage: A uniform circular disk of radius 0.2 m and mass 1 kg is pivoted at its top point C such that it can rotate freely around C in the XY plane, as shown in the figure. Initia 2026A solid cylinder having radius R and length L is slipping on a rough horizontal plane. At time t=0 the cylinder has a translational velocity v₀=49 m/s, perpendicular to its axis an 2026A solid sphere ( A ) of mass 5m and a spherical shell ( B ) of mass m , both having same radius, are placed on a rough surface. When a force of same magnitude is applied tangential 2026A solid sphere of radius 4 cm and mass 5 kg is rotating (rotation axis is passing through the centre of the sphere) with an angular velocity of 1200 rpm. It is brought to rest in 1 2026 Full Rotational Motion list All Most Important Selected Qs for JEE Advanced PYQs